I have a 350/700R4 with the SD system. I have installed this system in my 1964 GMC truck......

I have a new set of Dolphin gauges hooked up to this.....

I get no reading on my speedo.....I have tried setting all the DIP switches as recommended, but still nothing....

All my other gauges work fine....

What can I do to check if my VSS is sending a signal to my speedo?

Can I measure voltage off the back of the speedo?

I am not getting any error codes at all from the computer....


Let me know if you need any more information.

Thanks

Chad

Do you have access to a scan tool? Plug the scan tool into the ALDL port and see if the computer is getting a VSS signal.

Are you using a cable drive speedo or a electronic speedo? The SD computer is expecting an electronic signal and it outputs an electronic signal to the speedometer.

electric speedo.....

I've looked at the pin-outs but don't know if I can read a voltage to see if it works..

anyone have any idea...

I am going to try and find a handheld scanner......

You might be able to take off the VSS from the transmission and spin it with a variable speed drill motor. Might help in trouble shooting.